Alan Gentry stood by his ball off the seventh fairway and took a few practice swings. He had no club in his hand. Like any other golfer, he was grooving a perfect shot in his mind before selecting the proper stick. But unlike most, he had no right arm in his socket. So when a car drove by Gentry as he warmed up, four heads whipped back to catch the sight. Did you see that? Was that guy actually warming up with one arm?

The golfers who gathered in Las Vegas in October for the North American One-Armed Golfer Association championships...